import java.awt.Color;
import java.awt.Graphics;

import javax.vecmath.*;

public class Particle 
{
	/** Undeformed/material Position. */
    Point2d  x0 = new Point2d();
    
	/** Deformed Position. */
    Point2d  x = new Point2d();
    
    /** Velocity. */
    Vector2d v = new Vector2d();

    /** Force accumulator. */
    Vector2d f = new Vector2d();
	
	Particle( Point2d x0 )
	{
		this.x.set(x0);
	}
	
	public void advanceTime()
	{
		f.set(0, -10);
		x.y += 1; 
	}
	
	public void display(Graphics g)
	{
		g.setColor(Color.BLACK);
		g.fillOval((int)x.x, (int)x.y, 10, 10);

	}

}
